1. Field of the Invention
The present invention relates to an auto-folder type cellular phone whose folder cover opens or closes automatically. More specifically, the present invention relates to an auto-folder type cellular phone with a variable opening and closing velocity, which enables a user to vary a driving voltage of his/her cellular phone whenever desired, whereby the user, unlike a conventional auto-folder type cellular phone having a fixed (or constant) driving voltage, now can open or close his/her cellular phone more quickly or slowly anyway he/she wants.
2. Description of the Related Art
In general, a cellular phone (or mobile phone) indicates a terminal for providing subscribers of cell phones with mobile communication services available in a designated coverage within a service area by changing part of subscriber's locally dedicated line to a radio network. While a conventional communication service allows a subscriber to make a call in a rooted, stationary place using a given line number, the cellular phone enables the mobile subscriber to make a phone call using his/her logical personal number any place he/she wants.
For easiness and convenience of use, the cellular phone has been in great demand. To keep abreast with such tendency, the mobile phone industry has been trying to develop a smaller and multi-functioned mobile phone to meet diverse demands of consumers.
Typically, the cellular phone can be divided into several groups in accordance with its shape and whether number buttons (or functional menu buttons) are exposed to the outside: bar type cellular phone, flip type cellular phone whose number (functional menu) buttons are covered by a cover, and a folder type cellular phone whose body is folded in half. As more people prefer a smaller sized cell phone, the folder type mobile phone has been more popularized than the other types.
For all that, the conventional folder type cellular phone gives another problem to subscribers that its relatively heavy folder requires its subscriber to use his/her both hands to open up the handset, that is, one hand for holding the main body of the phone and the other hand for opening/closing the handset.
Several approaches have been developed to deal with this problem. One such approach involves the use of a driving device (or drive) to open/close the handset automatically.
FIG. 1 is a perspective view of an auto-folder type cellular phone. As depicted in the drawing, the cellular phone 201 includes a main body 202 and a folder 203. The main body 202 is typically mounted with number (functional menu) buttons 204, a microphone 205, many kinds of built-in components for incoming/outgoing calls, and a battery pack 206 for power supply.
The folder 203 includes a display 207 for displaying every kind of call information and functional menu information available in the phone, a speaker 208, and other necessary built-in components.
Generally, the folder 203 of the folder type cellular phone 201 is connected to the main body 202, being supported by a hinge means. Thanks to the hinge, the folder 203 folds (closes) or opens, moving forward or backward. To automate this move, there is a switch (i.e. opening/closing button) on the upper right corner of the main body in the form of a signal applying unit 209.
As illustrated in FIG. 2, a subscriber can easily open up or close the folder with one hand by operating the signal applying unit 209. The most important thing to consider before designing such cellular phone is that the folder should be opened or closed not only in an automatic mode but also manual mode in case of an unexpected situation.
FIG. 3 is a cross-sectional view of the conventional auto-folder type cellular phone, representing a state that a revolving unit 211 and a fixating unit 210 positioned at one side of the main body are joined together, wherein the revolving 211 includes a power generating means for automatically opening and closing the folder in response to a signal from the signal applying unit and a power transfer means.
FIG. 4 is a cross-sectional view of the revolving unit 211 and the fixating unit 210, the fixating unit 210 being placed on both sides of the main body, and the revolving unit 211 being installed between the fixating units 210 in the form of a module housing. Especially, the drawing captures an essential part of the cellular phone in that a driving device for automatically opening and closing the folder is installed inside the revolving unit 211.
As shown in FIG. 4, the conventional auto-folder type cellular phone includes the fixating unit 210 on both sides of the main body; the revolving unit 211 connected to one side of the folder 203, the folder 203 being supported by the fixating unit to be revolvable; a motor 212 operating as a power generating means attached inside of the revolving unit and working with the signal applying unit that is controlled (or operated) by a user; a reduction gear 213 linked to an output end of the motor 212 for decelerating a revolving rate and at the same time, preventing reversion; a first coupler 215, capable of revolving, linked to the reduction gear 213; a second coupler 216, capable of sliding, mounted on the fixating unit; and an elastic means 217 for providing an elastic force, that is mounted inside the revolving unit. Also, an end portion of the first coupler 215 and an end portion of the second coupler 216 are selectively geared with each other.
Therefore, when a subscriber of the auto-folder type cellular phone operates the signal applying unit 209 to open up the folder 203, the folder first revolves within a predetermined time having the first coupler 215 and the second coupler 216 as a fixed point, halts, and then opens. If the subscriber wants to shut the folder 203, all he or she needs to do is operate the signal applying unit 209 again. In such case, the motor is driven to an opposite direction for a predetermined period of time so as to shut the folder. On the other hand, if the cellular phone is in a manual mode, there is created a slip between the first coupler 215 and the second coupler 216, so when the folder reaches a certain position, it is opened and closed by the elastic force.
Despite several merits found in the auto-folder type cellular phone, a problem still arises in that subscribers of the conventional auto-folder type cellular phones cannot necessarily control the opening/closing velocity of the folder since the driving voltage thereof is set to be constant. Hence, when the subscribers want to vary (i.e. speed up or slow down) the opening/closing velocity of the folder, the conventional auto-folder type cellular phone could not satisfy their demand.